The Brewing Process
The Brewing Process The principals of brewing have remain unchanged throughout the millennia, stretching all the way back to when it probably first began, 11,500 years ago, in Neolithic times, when cereals were first farmed. The basic ingredients remain the same: water, a starch source, and yeast. While hops didn’t come into the picture until later, some sort of equivalent has always existed, be it fruit, vegetables, spices, etc. While the first beer ever made was likely due to an accident (a very happy one), the process has become much more refined over time. Malting This first step to making beer is the treatment of the grain, the starch source, usually barley. The grain is soaked, or steeped, for a period of time, usually just under a couple of days. This will cause the grain to start germinating. They are then placed either out on the floor of a germination room and raked, or into rotating drums (which is the cheaper practice). The goal here is to aerate and dry the grains. On a molecular level, the starches are breaking down into shorter lengths, which will make them more easily consumed by the yeast. The grains are now in a state known as green malt. The brewer doesn’t want the grains to full germinate, so he places them into a large oven, a kiln, and slowly increases the temperature, so as not to disturb the enzymes. The length of the kilning ''also has a big influence on the flavour of the beer. The more you roast, the more intense the flavours produced: * Gently kilned grains will be light, with soft, delicate flavours. * More intense kilning will result in a darker and sweeter malt, with biscuit toffee flavours. * The darkest malts are full of dark chocolate and roasted coffee notes. Once kilning is completed, we have the finished malt. '''Milling' After a period of storage, the brewer cracks the grains in a process known as milling. The purpose of this is to allow water access to the centre of the grain. However, you don`t want to completely destroy the husk, as this acts as a barrier, preventing the extraction of tannins and other undesirable components. The resulting product resembles coarse flour, known as grist. Mashing By this point, the starches in the grain have been sufficiently exposed. However, it`s not the starches themselves that are needed, but the sugars that they can be converted into. The grist is mixed with hot water and placed in a large vessel, known as a mash tun. The two combined are now referred to as a cereal mash. At this point, sometimes unmalted barley is added to impart extra flavour (Guinness, for example, adds roasted unmalted barley to give it its dark colour and rich flavour). During this process, naturally-occurring enzymes convert the starches into sugar. The resulting liquid is now referred to as the wort (from the German word “root,” as this liquid is considered the root of the beer). The temperature of the mash will be increased to deactivate the enzymes, and then the whole wort will be strained through the bottom of the mash tun. Boiling The resulting liquid is placed into a kettle, referred to as a copper (even though it is now quite often made of stainless steel), and, as the name suggests, boiled. This is a very important part of the process as far determining how the beer will taste, as boiling reduces the acidity of the wort, and undesirable flavours are eliminated. Hops and other flavouring agents, such as spices and herbs are added. During the boiling, the aroma of hops can be lost, so some are added later in the process. With lager, they are added in the later stages of the boil, while, with some ales, some are added at the very end, a process known as dry-hopping. Whirlpooling / Hopbacking After boiling, the liquid is strained, removing the residue of the hops and other additives. There are two ways to do this. One is to use centrifugal force, rotating the liquid to cause all the denser solids (hot trub) into a cone in the centre of the tank. This process is known as whirlpooling. These solids settle int the middle of the tank, and stay there when the wort is drained. An alternative, or sometimes, additional method of removing the hot trub is to run it through a vessel known as a hop back. This is the original method of filtering. Whole fresh hops function as a filter, and also add additional hops flavour and aroma. Wort Cooling Before yeast can be added, the wort must be lowered to a temperature(20°-26°C) that will allow the yeast to ferment. The wort is pumped into a heat exchanger. Cold water is run through pipes, or ridged plates, that come into contact with the wort, which lowers its temperature quite quickly. It is then aerated with sterile air. Fermenting This is the point in the process where the brewer can find himself at a crossroads. Which method of fermentation will he choose? Warm, cool, or wild/spontaneous? Regardless of their choice, the main desired components of fermentation are the same: alcohol, and carbon dioxide. However, the type of yeast used will also impart certain flavours and aromas to the beer. The yeast is added to the wort, or pitched, to begin the fermentation process. Secondary Fermentation A nasty by-product of fermentation is the formation of unwanted flavours and compounds that affect both the flavour of your beer, and the pain of your hangover. After the primary fermentation, the beer is transferred to another container, with the residue being left behind, having sunk to the bottom. If the secondary fermentation takes place in a large vessel, the yeast will settle to the bottom, yielding a much clearer beer. If secondary fermentation takes place in the bottle (bottle-conditioning), the resulting beer can be hazy, as a small amount of sugars and yeast will have been added. The more dense the yeast, however, the more likely it is to settle, reducing the level of murkiness. The benefits of bottle-conditioning are twofold: it will provide the carbonation for the beer, and it will give the beer a much longer shelf-life, as the yeast will prevent compounds in the beer from breaking down into unpleasant flavours, as it would in a filtered beer.